Beyond ℓ1 sparse coding in V1
Fig 5
The largest number of ϕ vectors responding maximally to a particular orientation are the ones with a preference towards the vertical orientation, with this subset also showing the sharpest orientation tuning (as indicated by their circular variance).
A: Polar plots of the proportion of ϕ vectors responding maximally to an orientation for ISTA, CEL0, ℓ1/2, and hard thresholding. B: Polar plots of the mean circular variance of ϕ vectors binned according to their preferred orientation.